| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| /** |
| * The hll package contains a high performance implementation of Phillipe |
| * Flajolet's HLL sketch with significantly improved error behavior. |
| * |
| * <p>If the ONLY use case for sketching is counting uniques and merging, the |
| * HLL sketch is the highest performing in terms of accuracy for space |
| * consumed. For large counts, this HLL version will be 2 to 16 times |
| * smaller for the same accuracy than the Theta Sketches. |
| * |
| * <p>HLL sketches do not retain any of the hash values of the associated unique identifiers, |
| * so if there is any anticipation of a future need to leverage associations with these |
| * retained hash values, Theta Sketches would be a better choice.</p> |
| * |
| * <p>HLL sketches cannot be intermixed or merged in any way with Theta Sketches. |
| * </p> |
| * |
| * @author Lee Rhodes |
| * @author Kevin Lang |
| */ |
| |
| package org.apache.datasketches.hll; |